2,631 research outputs found

    The influence of a stressful microenvironment on tumor exosomes: a focus on the DNA cargo

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    Exosomes secreted by tumor cells, through the transport of bioactive molecules, reprogram the surroundings, building a microenvironment to support the development of the tumor. The discovery that exosomes carry genomic DNA reflecting that of the tumor cell of origin has encouraged studies to use them as non-invasive biomarkers. The exosome-mediated transfer of oncogenes suggested a new mechanism of malignant transformation that could play a role in the formation of metastases. Several studies have examined the role of tumor exosomes on the modulation of the tumor microenvironment, but relatively few have been directed to assess how stressful stimuli can influence their production and cargo. Understanding the changes in exosome loads and the production pattern of the stressed tumor cell may uncover actionable mechanisms responsible for tumor progression

    Estructura de las principales especies arbóreas en el Parque Cruce Caballero y su similitud floristica com areas de Argentina y de Brasil.

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    El presente trabajo tuvo como objetivo estudiar la estructura fitosociológica y la similitud florística entre áreas con selvas estacionales y mixtas de Misiones, Argentina y de Brasil. El Parque Cruce Caballero tiene 522 hectáreas donde se utilizó el método de las parcelas múltiples de 20 x 10 m para árboles a partir de 5 cm de diámetro a la altura de 1,30 (DAP). Se registraron e identificaron todas las especies arbóreas midiéndose el DAP y altura en tres compartimientos ambientales considerados: Latossolo vermelho, Neossolo litólico y Gleissolo Melánico. La Araucaria angustifolia (Bertol.) Kuntze domina el estrato superior en el primer compartimiento acompañada de Sorocea bonplandii (Baill.) W.C.Burger, Lanj. & Boer, Cabralea canjerana (Vell.) Mart., Ocotea lancifolia Mez y Apuleia leiocarpa J.F.Macbr.. La araucaria está ausente en el Neossolo Litólico donde predominan Gymnanthes concolor Müll.Arg., Trichilia claussenii C.DC., Apuleia leiocarpa, Pilocarpus pennatifolius Lem. y Sorocea bomplandii. La araucaria está escasamente representada en Gleissolo Melánico donde predominan Parapiptadenia rigida (Benth.) Brenan, Alchornea triplinervia Müll.Arg., Luehea divaricata Mart., Erythrina falcata Benth. y Myrsine gardneriana A.DC.. Comparando la similitud florística con otras áreas de la región se encontró que Cruce Caballero se asemeja a áreas con Selvas estacionales y presenta escasa similitud con a las selvas mixtas con araucaria de Brasil

    Characterization of self-injected electron beams from LWFA experiments at SPARC_LAB

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    The plasma-based acceleration is an encouraging technique to overcome the limits of the accelerating gradient in the conventional RF acceleration. A plasma accelerator is able to provide accelerating fields up to hundreds of GeV/mGeV/m, paving the way to accelerate particles to several MeV over a short distance (below the millimetre range). Here the characteristics of preliminary electron beams obtained with the self-injection mechanism produced with the FLAME high-power laser at the SPARC_LAB test facility are shown. In detail, with an energy laser on focus of 1.5 J1.5\ J and a pulse temporal length (FWHM) of 40 fs40\ fs, we obtained an electron plasma density due to laser ionization of about 6×1018 cm36 \times 10^{18}\ cm^{-3}, electron energy up to 350 MeV350\ MeV and beam charge in the range (50100) pC(50 - 100)\ pC.Comment: 6 pages, 11 figures, conference EAAC201

    Laser cutting of different polymeric plastics (PE, PP and PC) by a CO2 laser beam

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    Thiswork investigates the application of theCO2 laser cutting process to three thermoplastic polymers, polyethylene (PE), polypropylene (PP), polycarbonate (PC) in different thicknesses ranging from 2 to 10 mm. The process parameters examined were: laser power, range of cutting speed, type of focusing lens, pressure and flow of the covering gas, thickness of the samples. Furthermore, the values of kerf widths on top (Lsup) and bottom (Linf ) thicknesses, the melted transverse area, the melted volume per unit time and surface roughness values (Ra) on cut edges were also measured

    On the welding of different materials by diode laser

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    In technical literature, there are few papers about the use of diode lasers in material processing and particularly in metal welding. In this paper, different materials, according to specific and particular industrial needs and requests, have been tested with a welding process by a diode laser, emitting a 808 nm laser radiation. Beads on plate have been studied. The goal was to evaluate the maximum weldable thickness and define the best process parameters for each material. The experimental evaluation has been carried out considering the following parameters: power level, welding speed (WS), shielding gas, gas nozzle and orientation of the focused elliptical spot as to the welding direction

    Diversidade e distribuição espacial de bromeliáceas epifíticas do Altíssimo Rio Tibagi - Paraná - Brasil.

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    O presente estudo teve como objetivo caracterizar a diversidade e a distribuição espacial das bromeliáceas epifíticas na região do altíssimo rio Tibagi, considerando os fatores geomorfológicos, pedológicos, climáticos e vegetacionais. A avaliação fitossociológica das bromeliáceas foi realizada mediante instalação de parcelas em número variável nas três áreas de estudo. O levantamento florístico foi complementado por observações nas áreas adjacentes às parcelas, respeitando a compartimentação geomorfológica, pedológica e vegetacional. Foram registradas onze espécies de bromeliáceas no total, tendo sido sete delas observadas na área da cabeceira do rio Tibagi, oito no cânion e nove na floresta da foz do rio Bugio. A riqueza foi relacionada, principalmente, com as condições macro e microclimáticas. A umidade fornecida pelas nuvens e chuvas formadas na cuesta do segundo planalto, assim como, em microescala, a umidade atmosférica gerada pelas cachoeiras existentes no cânion e originada da evaporação da água dos Organossolos, é o fator climático fundamental na definição dos padrões encontrados. Considerando a distribuição horizontal das espécies, a diminuição de bromeliáceas da porção mais próxima ao canal para a mais distante está atrelada ao gradiente microclimático, formado pela redução em umidade relativa associada à diminuição em luminosidade
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